Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Immunisation or vaccination - what's the difference?

3-minute read

The terms ‘vaccination’ and ‘immunisation’ don’t mean quite the same thing. Vaccination is the term used for getting a vaccine – that is, actually getting the injection or taking an oral vaccine dose. Immunisation refers to the process of both getting the vaccine and becoming immune to the disease following vaccination.

How does immunisation work?

All forms of immunisation work in the same way. When someone is injected with a vaccine, their body produces an immune response in the same way it would following exposure to a disease but without the person getting the disease. If the person comes in contact with the disease in the future, the body is able to make an immune response fast enough to prevent the person developing the disease or developing a severe case of the disease.

What is in vaccines?

Some vaccines contain a very small dose of a live, but weakened form of a virus. Some vaccines contain a very small dose of killed bacteria or small parts of bacteria, and other vaccines contain a small dose of a modified toxin produced by bacteria.

Vaccines may also contain either a small amount of preservative or a small amount of an antibiotic to preserve the vaccine. Some vaccines may also contain a small amount of an aluminium salt which helps produce a better immune response.

How long do immunisations take to work?

In general, the normal immune response takes approximately 2 weeks to work. This means protection from an infection will not occur immediately after immunisation. Most immunisations need to be given several times to build long-lasting protection.

A child who has been given only 1 or 2 doses of the DTPa vaccine is only partially protected against diphtheria, tetanus and pertussis (whooping cough), may become sick if exposed to these diseases until they have all the doses they need. However, some of the new vaccines, such as the meningococcal ACWY vaccine, provide long-lasting immunity after only one dose.

How long do immunisations last?

The protective effect of immunisations is not always lifelong. Some, like tetanus vaccine, can last up to 30 years, after which time a booster dose may be given. Some immunisations, such as whooping cough vaccine, give protection for about 5 years after a full course. Influenza immunisation is needed every year due to frequent changes to the type of flu virus in the community.

Is everyone protected from disease by immunisation?

Even when all the doses of a vaccine have been given, not everyone is protected against the disease. Measles, mumps, rubella, tetanus, polio, hepatitis B and Hib vaccines protect more than 95% of children who have completed the course. One dose of meningococcal ACWY vaccine at 12 months protects over 90% of children.

Three doses of whooping cough vaccine protects about 85% of children who have been immunised, and will reduce the severity of the disease in the other 15% if they do catch whooping cough. Booster doses are needed because immunity decreases over time.

More information

In Australia, vaccines are funded by the National Immunisation Program and protect millions of Australians from vaccine-preventable diseases.

If you have any questions, you can speak to your doctor or call healthdirect on 1800 022 222.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: April 2019

Need more information?

These trusted information partners have more on this topic.

Top results

Immunisation

The articles in this section relate to immunisation, vaccines and vaccination safety.

Read more on WA Health website

Immunisation or vaccination - what's the difference?

What's the difference between immunisation and vaccination?

Read more on Pregnancy, Birth & Baby website

Immunisation records | NCIRS

Your immunisation history statement has all your vaccines that have been recorded on the Australian Immunisation Register (AIR)

Read more on National Centre for Immunisation Research and Surveillance (NCIRS) website

Immunisation for your child

Immunisation is a simple, safe and effective way of protecting children against certain diseases. Discover more about childhood vaccinations.

Read more on Pregnancy, Birth & Baby website

HPV vaccine | AusVaxSafety

From January 2018 a new HPV vaccine, Gardasil9, is being funded under the National Immunisation Program

Read more on National Centre for Immunisation Research and Surveillance (NCIRS) website

Optional vaccinations | SKAI

The vaccinations children receive at 6 weeks, 4 months, 6 months, 12 months, 18 months and 4 years are all part of the National Immunisation Program

Read more on National Centre for Immunisation Research and Surveillance (NCIRS) website

Where can I get immunised? | Australian Government Department of Health

You can get vaccinations from a range of vaccination providers, including your local GP and school-based immunisation programs.

Read more on Department of Health website

Immunisation schedules | NCIRS

The Australian National Immunisation Program (NIP) is funded by the Australian government and implemented by state and territory departments of health

Read more on National Centre for Immunisation Research and Surveillance (NCIRS) website

Year 8 immunisation program

Immunisations are offered free to all year 8 students – diphtheria-tetanus-pertussis, chickenpox, human papillomavirus.

Read more on WA Health website

NCIRS position statement on HPV vaccination | NCIRS

Immunisation against human papillomavirus (HPV) has been available under Australias National Immunisation Program since 2007 and is highly effective in preventing infection with HPV

Read more on National Centre for Immunisation Research and Surveillance (NCIRS) website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo